Saliva biomonitoring of atrazine exposure among herbicide applicators

A field study was conducted in which saliva samples were collected from a c ohort of herbicide applicators during the pre-emergent spray season in Ohio in 1996. Atrazine concentrations were detected in human saliva samples usi ng an enzyme-linked immunosorbent assay (ELISA) method. Trend due to atrazi ne exposure and subsequent elimination in the body were evidenced by the te mporal pattern of decreasing atrazine concentrations in saliva over time. M edian salivary concentrations of atrazine on non-spray days were significan tly lower than on spray days for each sampling time (MannWhitney U-Wilcoxon rank sum test, P < 0.01). Within spray days, median salivary atrazine conc entrations were significantly higher on days atrazine was sprayed than on d ays herbicides other than atrazine were sprayed for each sampling time (Man n-Whitney U-Wilcoxon rank sum test, P = 0.02 for 4-6 p.m. samples, P = 0.04 for bedtime samples, P = 0.03 for next-morning samples). Median salivary a trazine concentrations on days atrazine was sprayed were higher than the me dian concentration for the corresponding sampling time on non-spray days an d on days when other herbicides were sprayed. Salivary concentration of atr azine is a plausible indicator of those days in which atrazine spraying was likely to have occurred. Salivary concen trations of atrazine not only ref lect exposures resulting from spraying atrazine, but also exposures from ot her field activities where applicators may come in contact with atrazine. T he results of this study confirmed data from animal experiments that atrazi ne is able to cross the cell membranes of salivary glands, and can be measu red in human saliva with high sensitivity. The sampling method itself is co nvenient and easy to use in the field, with a high compliance rate, and ana lytical procedures are rapid and inexpensive. It is, therefore, concluded t hat saliva sampling of atrazine exposure among herbicide applicators is a f easible biomonitoring method.